We'd agree that a diesel still makes sense for your mileage. A Skoda Octavia or the bigger Superb should be a dependable choice – they'll be very comfortable and cheap to run, too. Also look at the Toyota Avensis (a very dull car but one that'll last forever) or a Honda Civic. You could also look at SUVs like the Honda CR-V if you want a bit more comfort, although they'll have slightly higher running costs.